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Drag and drop for sort and delete implementation.
/*
* Copyright (c) 2014-2015 Zhang Hai
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.yourapplication;
import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.view.DragEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AccelerateDecelerateInterpolator;
// TODO: Provide scrolling at edge, see
// https://github.com/justasm/DragLinearLayout/blob/master/library/src/main/java/com/jmedeisis/draglinearlayout/DragLinearLayout.java
// and
// https://github.com/nhaarman/ListViewAnimations/blob/master/lib-manipulation/src/main/java/com/nhaarman/listviewanimations/itemmanipulation/dragdrop/DragAndDropHandler.java
public class DragUtils {
private DragUtils() {}
public static void setupDragSort(View view, final DragListener listener) {
view.setOnDragListener(new View.OnDragListener() {
@Override
public boolean onDrag(final View view, DragEvent event) {
ViewGroup viewGroup = (ViewGroup)view.getParent();
DragState dragState = (DragState)event.getLocalState();
switch (event.getAction()) {
case DragEvent.ACTION_DRAG_STARTED:
if (view == dragState.view) {
view.setVisibility(View.INVISIBLE);
listener.onDragStarted();
}
return true;
case DragEvent.ACTION_DRAG_LOCATION: {
if (view == dragState.view){
break;
}
int index = viewGroup.indexOfChild(view);
if ((index > dragState.index && event.getY() > view.getHeight() / 2)
|| (index < dragState.index && event.getY() < view.getHeight() / 2)) {
swapViews(viewGroup, view, index, dragState);
} else {
swapViewsBetweenIfNeeded(viewGroup, index, dragState);
}
break;
}
case DragEvent.ACTION_DRAG_ENDED:
if (view == dragState.view) {
view.setVisibility(View.VISIBLE);
listener.onDragEnded();
}
break;
}
return true;
}
});
view.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View view) {
view.startDrag(null, new View.DragShadowBuilder(view), new DragState(view), 0);
return true;
}
});
}
public static void setupDragDelete(View view, final ViewGroup viewGroup,
final OnDragDeletedListener listener) {
view.setOnDragListener(new View.OnDragListener() {
@Override
public boolean onDrag(View view, DragEvent event) {
switch (event.getAction()) {
case DragEvent.ACTION_DRAG_ENTERED:
view.setActivated(true);
break;
case DragEvent.ACTION_DRAG_EXITED:
view.setActivated(false);
break;
case DragEvent.ACTION_DROP:
DragState dragState = (DragState)event.getLocalState();
removeView(viewGroup, dragState);
listener.onDragDeleted();
break;
case DragEvent.ACTION_DRAG_ENDED:
// NOTE: Needed because ACTION_DRAG_EXITED may not be sent when the drag
// ends within the view.
view.setActivated(false);
break;
}
return true;
}
});
}
private static void swapViewsBetweenIfNeeded(ViewGroup viewGroup, int index,
DragState dragState) {
if (index - dragState.index > 1) {
int indexAbove = index - 1;
swapViews(viewGroup, viewGroup.getChildAt(indexAbove), indexAbove, dragState);
} else if (dragState.index - index > 1) {
int indexBelow = index + 1;
swapViews(viewGroup, viewGroup.getChildAt(indexBelow), indexBelow, dragState);
}
}
private static void swapViews(ViewGroup viewGroup, final View view, int index,
DragState dragState) {
swapViewsBetweenIfNeeded(viewGroup, index, dragState);
final float viewY = view.getY();
AppUtils.swapViewGroupChildren(viewGroup, view, dragState.view);
dragState.index = index;
AppUtils.postOnPreDraw(view, new Runnable() {
@Override
public void run() {
ObjectAnimator
.ofFloat(view, View.Y, viewY, view.getTop())
.setDuration(getDuration(view))
.start();
}
});
}
private static void removeView(final ViewGroup viewGroup, DragState dragState) {
final int oldViewGroupLayoutParamsHeight = viewGroup.getLayoutParams().height;
final int oldViewGroupHeight = viewGroup.getHeight();
viewGroup.removeView(dragState.view);
int childCount = viewGroup.getChildCount();
for (int i = dragState.index; i < childCount; ++i) {
final View view = viewGroup.getChildAt(i);
final float viewY = view.getY();
AppUtils.postOnPreDraw(view, new Runnable() {
@Override
public void run() {
ObjectAnimator
.ofFloat(view, View.Y, viewY, view.getTop())
.setDuration(getDuration(view))
.start();
}
});
}
final int newViewGroupHeight = measureViewGroupHeight(viewGroup);
if (viewGroup.getChildCount() > 0) {
// Prevent the flash of the new height before the start of our animation.
AppUtils.setViewLayoutParamsHeight(viewGroup, oldViewGroupHeight);
// Wait until the OnPreDraw of the last child is called for syncing the two animations on
// View and ViewGroup.
AppUtils.postOnPreDraw(viewGroup.getChildAt(viewGroup.getChildCount() - 1), new Runnable() {
@Override
public void run() {
animateViewGroupHeight(viewGroup, oldViewGroupLayoutParamsHeight,
oldViewGroupHeight, newViewGroupHeight);
}
});
} else {
// Animate now since there is no children.
animateViewGroupHeight(viewGroup, oldViewGroupLayoutParamsHeight, oldViewGroupHeight,
newViewGroupHeight);
}
}
private static int measureViewGroupHeight(ViewGroup viewGroup) {
View parent = (View)viewGroup.getParent();
int widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(
parent.getMeasuredWidth() - parent.getPaddingLeft() - parent.getPaddingRight(),
View.MeasureSpec.AT_MOST);
int heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
viewGroup.measure(widthMeasureSpec, heightMeasureSpec);
return viewGroup.getMeasuredHeight();
}
private static void animateViewGroupHeight(final ViewGroup viewGroup,
final int oldLayoutParamsHeight, int oldHeight,
int newHeight) {
ValueAnimator viewGroupAnimator = ValueAnimator
.ofInt(oldHeight, newHeight)
.setDuration(getDuration(viewGroup));
viewGroupAnimator.setInterpolator(new AccelerateDecelerateInterpolator());
viewGroupAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
int animatedValue = (int) animation.getAnimatedValue();
AppUtils.setViewLayoutParamsHeight(viewGroup, animatedValue);
}
});
viewGroupAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
AppUtils.setViewLayoutParamsHeight(viewGroup, oldLayoutParamsHeight);
}
});
viewGroupAnimator.start();
}
private static int getDuration(View view) {
return view.getResources().getInteger(android.R.integer.config_shortAnimTime);
}
public static interface DragListener {
public void onDragStarted();
public void onDragEnded();
}
public static interface OnDragDeletedListener {
public void onDragDeleted();
}
private static class DragState {
public View view;
public int index;
private DragState(View view) {
this.view = view;
index = ((ViewGroup)view.getParent()).indexOfChild(view);
}
}
}
/*
* Copyright (c) 2014-2015 Zhang Hai
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.yourapplication;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
public class AppUtils {
private AppUtils() {}
public static void postOnPreDraw(View view, final Runnable runnable) {
final ViewTreeObserver observer = view.getViewTreeObserver();
observer.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
@Override
public boolean onPreDraw() {
if (observer.isAlive()) {
observer.removeOnPreDrawListener(this);
}
runnable.run();
return true;
}
});
}
public static void setViewLayoutParamsHeight(View view, int height) {
ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
layoutParams.height = height;
view.setLayoutParams(layoutParams);
}
public static void swapViewGroupChildren(ViewGroup viewGroup, View firstView, View secondView) {
int firstIndex = viewGroup.indexOfChild(firstView);
int secondIndex = viewGroup.indexOfChild(secondView);
if (firstIndex < secondIndex) {
viewGroup.removeViewAt(secondIndex);
viewGroup.removeViewAt(firstIndex);
viewGroup.addView(secondView, firstIndex);
viewGroup.addView(firstView, secondIndex);
} else {
viewGroup.removeViewAt(firstIndex);
viewGroup.removeViewAt(secondIndex);
viewGroup.addView(firstView, secondIndex);
viewGroup.addView(secondView, firstIndex);
}
}
}
@ncworm

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@ncworm

ncworm Sep 14, 2016

Restart app how to remember the last position?

ncworm commented Sep 14, 2016

Restart app how to remember the last position?

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